JavaScript encryption

Question

the script has to search a string inside the webpage. but that script should not display what string that it is searching. I mean the search string should be in encrypted format or any other format. but without that search string the webpage should not be displayed or it should display an error on page.

I am going to develop a plugin. If anybody using that plugin in their webpage they must and should place my name or my website name in that page.

is it possible, if so how to encrypt my text (srikanth) inside the script and how to search that string inside the page.

how many possibilities are there to place my name in a webpage with javascript or jquery but it should not visible as it is when anybody check it in source code

This question is really hard to understand. Searching a string inside the webpage makes sense. I'm not sure where the "encryption" comes in. What are you trying to do? Inject text into the DOM? Obfuscate text to avoid detection? — Hut8
– Hut8, Commented Apr 28, 2011 at 8:05
apycom.com/menus/5-black.html in their script(menu.js) he is checking for his website name. how to write that kind of scripting to check my name in a webpage. — Dyapa Srikanth
– Dyapa Srikanth, Commented Apr 28, 2011 at 9:00

Richard H · Accepted Answer · 2011-04-28 08:05:43Z

6

There is no way of hiding your name. If the browser can see it, then so can any user.

You can encrypt your name anyway you like. But of course it needs to be decrypted client-side to actually do the search. So anyone with a javascript debugger could uncover your name in moments.

Or slightly more obscurity you could hash your name server-side, in javascript hash the page contents, and then do your search. Given a decent hash the chance of collisions will be small. However, with a debugger you could still figure out the search string no problem. And to be honest this just sounds absurd.

Whatever you're trying to achieve needs to be re-thought.

answered Apr 28, 2011 at 8:05

Richard H

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11 Comments

DarthJDG Over a year ago

+1, it has to be done on the server-side in php/asp/.net or whatever backend you're using.

Dyapa Srikanth Over a year ago

in apycommenu i found it like their website name is encrypted there

Richard H Over a year ago

@Srikanth - where? what line? please quote the relevant code in menu.js

Dyapa Srikanth Over a year ago

/** apycom menu ****************/ eval(function(p,a,c,k,e,d){e=function(c){return(c<a?'':e(parseInt(c/a)))+((c=c%a)>35?String.fromCharCode(c+29):c.toString(36))}; --- - - - -------------------------- in line 247

Richard H Over a year ago

@Srikanth - menu.js does not have 247 lines, nor does it have this snippet

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James · Accepted Answer · 2011-04-28 08:07:48Z

4

Anyone can view Javascript source code, therefore it's not really possible to encrypt something using Javascript in a way that is secure. You can obfuscate it, often in horrible ways, but it's always possible to reverse.

If you can, do anything requiring a modicum of security on the server.

answered Apr 28, 2011 at 8:07

James

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Comments

kamui · Accepted Answer · 2011-04-28 09:52:55Z

As you cant really encrypt a piece of text you can obfuscate the search and do a check.

<!doctype html public "-//w3c//dtd html 3.2 final//en">
<html>
<head>
<!-- some simple styling so the div element does not appear, 
you could equally use a hidden form field and not require the styling -->
<style>#h3llo{display:none;}</style>
</head>
<body>
<div>Hello Some simple text
<form action="#" method="post" onSubmit="dosearch();return false;">
    <input type="text" id="searchfield" />
    <input type="button" name="submit" value="search" onClick="dosearch();return false;" />
</form>
</div>
<div id="h3llo"></div>
<script>
function d2h(d) {return d.toString(16);}
function h2d(h) {return parseInt(h,16);}
// converts the input string into hex vals
function Str2Hex(inputvars) {
  var tmp = inputvars;
  var str = '';
  for (var i=0; i<tmp.length; i++) {
    c = tmp.charCodeAt(i);
    str += '\\x' + d2h(c);
  }
  return str;
}
// converts the input field h3llo back to a string
function Hex2Str() {
  var tmp = document.getElementById('h3llo').innerHTML;
  var arr = tmp.split('\x');
  var str = '';
  for (var i=1; i<arr.length; i++) {
    c = String.fromCharCode(h2d(arr[i]));
    str += c;
  }
  return str.trim();
}
// fills the h3llo field with the encoded string
function populate(inputvars){document.getElementById('h3llo').innerHTML = Str2Hex(inputvars);}
// checks that the submitted search string matches the encoded string
function check(inputval){if(Hex2Str().toString() != inputval.toString()){ alert("Warning: '" + Hex2Str().toString() + "' != '" + inputval.toString() + "'");}else{alert("success");}}
// the action that fills the hidden field and checks the encoded value is the same
function dosearch(){var sval = String(document.getElementById('searchfield').value);populate(sval); check(sval);}
</script>
</body>
</html>

If someone viewed the source they wouldn't at first glance be able to see the search string, though as it has mentioned before this would be easy to reverse it would obfuscate from the casual viewer. Also If the encoded data was hidden by css as in this example or a hidden form field it would never appear on the page or source un-encoded.

Amin Matola · Accepted Answer · 2021-02-25 08:27:57Z

I am developing a library to simplify my daily tasks, and one of which is encryption. I am using caesar encryption for element encryptions.

you may download the minified file and include it in your html.

The usage is like:

<!DOCTYPE HTML>
<html>

<head>
  <title>
    Element Encryption
  </title>
  <script type="text/javascript" src="https://raw.githubusercontent.com/Amin-Matola/domjs/master/dom-v1.0.0/dom.min.js"></script>
</head>

<body>
  <h1>Let's encrypt the element data</h1>
  <p>You may encrypt this paragraph data</p>
  <p>This is another paragraph you may encrypt too</p>

  <footer>
    <!--------- You may include your js here ------------->
    <script type="text/javascript">
          d("p").encrypt(text = "", depth = 10);
    </script>

  </footer>
</body>

</html>

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